jimc Wrote:-------------------------------------------------------> The Energizer Bunny has been replaced by the> Energizer Birdie!>> This form of transportation has one advantage, the> two stick RC transmitter may eliminate hand held> cell phone usage while flying

Are you kidding?The next gen will be controlled with a phone app ! ! !Since the "pilot" is riding in it, isn't it a "Hexcopter" rather than a drone?

.-----------------------------------------------WA. state, 1 mile south of the Canadian border,I am not at the end of the world, but you can see it from here.'66 Monza Coupe - 4spd, 140 Daily driver beater'67 Monza Vert. - PG, 140 Daily driver beater

Yeah, well I forgot to.I was thinking about that the whole time I watched it."Man, that thing needs a rollcage!"

.-----------------------------------------------WA. state, 1 mile south of the Canadian border,I am not at the end of the world, but you can see it from here.'66 Monza Coupe - 4spd, 140 Daily driver beater'67 Monza Vert. - PG, 140 Daily driver beater

Sorry, I don't believe it is a real video. Where are all of the battery packs?Even with the tub being plastic, you'd need to have a lot of power/thrust tolift a person of 100 lbs. or more. I could see this lifting a real person a fewfeet off of the ground, but not a complete flight. The video has been edited towhere a dummy or light weight manikin is substituted for the actual flight, andcontrolled remotely. The contraption with manikin probably weights 50 lbs. tops.You'll also notice the the person only moves on take off and landing. No headmovement of the helmet camera, always straight forward. If this video were true,then this would be definitive proof that you could cool your Corvair with anelectric fan.

To give you an example, some miniature J8 jet engines can produce 34 pounds ofthrust, is it possible that four of them can lift a 120-pound person off theground. So basically you'd need 136 lbs of thrust just to lift a 120 lbs personoff the ground.

If you watch the build video, you can see it does lift the guy. The battery packs are the rectangular boxes on each motor arm. Lithium ion batteries have amazing power density without being very big, that plus the fact that several exotic magnetic metals have been developed in recent years and the motors are able to produce thrust only dreamed of 20 years ago. The motors are brushless and "throttled" electronically. It is dangerous because the slightest problem with just one motor system would mean a crash, and even if shuts down automatically if it senses trouble, it might drop him in a bad place. I noticed in the "Bakery" video the forward movement was slow, probably because there wasn't enough thrust to maintain altitude at a higher speed.

Yes, I watched the build video, but let me give you a real world example. TheF-35B STOVL variant (one of the programs I am on) has a maximum takeoff weightof 50,000 lbs., with the thrust for vertical take-off in the range of 58,000lbs. and hover mode around 55,000 lbs. (They typically don't do vertical take-offs,it is a rolling short take-off).

While I have no doubt that this contraption was able to lift him off theground, it would have limited full flight capabilities with a real passenger.If you notice in the build video, the 3 guys carrying the contraption to thecenter of the gym are struggling to carry it, so I'm guessing with the waythey are lifting it, it is over 75 to 100 lbs. If the guy that does the flightweighs approximately 150 lbs., then the total weight is in the range of 225 to250 lbs range. They would need approximately 225 to 285 lbs of thrust just toget it off the ground (or 42 to 48 lbs of thrust each motor). We haven't evencalculated the drag for the forward movement. This is why in the video itshows him coming into the parking lot VERY slowly. It is because this isprobably the maximum forward velocity with a real human in it. The best DCmotors on the market today have an efficiency of just over 70%. They wouldhave to be running these motors close to 100% of their RPM range, which isreally quite dangerous.

I hate to burst your bubble, but as I stated, I still believe they were able todo the lift off with a VERY short flight, but the bulk of the video would haveto be with a light weight manikin for it to be possible. so another words a fake video.

I agree with Cepak.If you don't agree with his math, look at the video again.At the start of the flight, the left support appears to have four batteries tied to it. The end of the flight at the bakery now has all of the batteries tapped in place.The pavers on the ground are the same in both locations. Hard to say what that means.Those batteries appear to be about the same size as the Ryobi 40 Volt lithium-Ion on my lawn mower and they aren't that light. It looks like they have four batteries for each of the six motors. I bet there are 60 lbs of batteries on there.

Richard Wrote:-------------------------------------------------------> I agree with Cepak.> If you don't agree with his math, look at the> video again.> At the start of the flight, the left support> appears to have four batteries tied to it. The end> of the flight at the bakery now has all of the> batteries tapped in place.> The pavers on the ground are the same in both> locations. Hard to say what that means.> Those batteries appear to be about the same size> as the Ryobi 40 Volt lithium-Ion on my lawn mower> and they aren't that light. It looks like they> have four batteries for each of the six motors. I> bet there are 60 lbs of batteries on there.